Class DeflaterInputStream

java.lang.Object
java.io.InputStream
java.io.FilterInputStream
java.util.zip.DeflaterInputStream
All Implemented Interfaces:
Closeable, AutoCloseable
public class DeflaterInputStream extends FilterInputStream
Implements an input stream filter for compressing data in the "deflate" compression format.

Compressor Usage

A DeflaterInputStream created without specifying a compressor will create a compressor at construction time, and close the compressor when the input stream is closed.

If a compressor is specified when creating a DeflaterInputStream, it is the responsibility of the caller to close the compressor after closing the input stream.

API Note:
The close() method should be called to release resources used by this stream, either directly, or with the try-with-resources statement.
Since:
1.6
See Also:

  • Field Details

    • def

      protected final Deflater def
      Compressor for this stream.

    • buf

      protected final byte[] buf
      Input buffer for reading compressed data.

  • Constructor Details

    • DeflaterInputStream

      public DeflaterInputStream(InputStream in)
      Creates a new input stream and compressor with the default compression level and a default buffer size.

      The compressor will be closed when this input stream is closed.

      Parameters:
      in - input stream to read the uncompressed data to
      Throws:
      NullPointerException - if in is null

    • DeflaterInputStream

      public DeflaterInputStream(InputStream in, Deflater defl)
      Creates a new input stream with the specified compressor and a default buffer size.

      Closing this input stream will not close the given compressor.

      Parameters:
      in - input stream to read the uncompressed data to
      defl - compressor ("deflater") for this stream
      Throws:
      NullPointerException - if in or defl is null

    • DeflaterInputStream

      public DeflaterInputStream(InputStream in, Deflater defl, int bufLen)
      Creates a new input stream with the specified compressor and buffer size.

      Closing this input stream will not close the given compressor.

      Parameters:
      in - input stream to read the uncompressed data to
      defl - compressor ("deflater") for this stream
      bufLen - compression buffer size
      Throws:
      IllegalArgumentException - if bufLen <= 0
      NullPointerException - if in or defl is null

  • Method Details

    • close

      public void close() throws IOException
      Closes this input stream and its underlying input stream, discarding any pending uncompressed data.
      Specified by:
      close in interface AutoCloseable
      Specified by:
      close in interface Closeable
      Overrides:
      close in class FilterInputStream
      Throws:
      IOException - if an I/O error occurs
      See Also:

    • read

      public int read() throws IOException
      Reads a single byte of compressed data from the input stream. This method will block until some input can be read and compressed.
      Overrides:
      read in class FilterInputStream
      Returns:
      a single byte of compressed data, or -1 if the end of the uncompressed input stream is reached
      Throws:
      IOException - if an I/O error occurs or if this stream is already closed
      See Also:

    • read

      public int read(byte[] b, int off, int len) throws IOException
      Reads compressed data into a byte array. This method will block until some input can be read and compressed.
      Overrides:
      read in class FilterInputStream
      Parameters:
      b - buffer into which the data is read
      off - starting offset of the data within b
      len - maximum number of compressed bytes to read into b
      Returns:
      the actual number of bytes read, or -1 if the end of the uncompressed input stream is reached
      Throws:
      NullPointerException - if b is null
      IndexOutOfBoundsException - if len > b.length - off
      IOException - if an I/O error occurs or if this input stream is already closed
      See Also:

    • skip

      public long skip(long n) throws IOException
      Skips over and discards data from the input stream. This method may block until the specified number of bytes are skipped or end of stream is reached.
      Overrides:
      skip in class FilterInputStream
      Implementation Note:
      This method skips at most Integer.MAX_VALUE bytes.
      Parameters:
      n - number of bytes to be skipped. If n is zero then no bytes are skipped.
      Returns:
      the actual number of bytes skipped, which might be zero
      Throws:
      IOException - if an I/O error occurs or if this stream is already closed
      IllegalArgumentException - if n < 0
      See Also:

    • available

      public int available() throws IOException
      Returns 0 after EOF has been reached, otherwise always return 1.

      Programs should not count on this method to return the actual number of bytes that could be read without blocking

      Overrides:
      available in class FilterInputStream
      Returns:
      zero after the end of the underlying input stream has been reached, otherwise always returns 1
      Throws:
      IOException - if an I/O error occurs or if this stream is already closed

    • markSupported

      public boolean markSupported()
      Always returns false because this input stream does not support the mark() and reset() methods.
      Overrides:
      markSupported in class FilterInputStream
      Returns:
      false, always
      See Also:

    • mark

      public void mark(int limit)
      This operation is not supported.
      Overrides:
      mark in class FilterInputStream
      Parameters:
      limit - maximum bytes that can be read before invalidating the position marker
      See Also:

    • reset

      public void reset() throws IOException
      This operation is not supported.
      Overrides:
      reset in class FilterInputStream
      Throws:
      IOException - always thrown
      See Also: